Proportional spacing mechanism for typewriters



April 3, 1951 R. D. DODGE PROPORTIONAL SPACING MECHNISM FOR .TYPEWRITERS Filed July 8, 194s 8 Sheets-Sheet 1 R. D. DODGE 2,547,449

PROPORTIGNAL SPACING MECHANISM FOR TYPEWRITERS S'Sheets-Sheet 2 L@ NS April 3, 1951 Filed July 8, 1948 INVENTOR A. oe@ 5% ATTORNEY R. D. DODGE PROPORTIONAL SPACING MECHANISM FOR TYPEWRITERS pri 3, 3951 8 Sheets-Sheet 5 Filed July 8, 1948 m@ mh.,

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PROPORTIONL SPACING MECHANISM FOR TYPEWRITERS Filed July 8, 1948 8 Sheets- INVENTOR D. 50265 ATTO R N EY April 3, 1951 R. D. DODGE PROPORTIONAL SPACING MECHANISM FOR TYPEWRITERS Filed July s, 1948 8 Sheets-Sheet 5 April 3, 1951 V R. D. DODGE 2,547,449

PROPORTIONAL SPACING MECHNISM FOR TYPEWRITERS Filed July s, 1948 FB@ HB 8 Sheets-Sheet 6 R. .0. .D00 G5 ATTORN EY Aprii 3i, 1951 R. D. DODGE 2,547,449

RoPoRTIoNAL sPAcING MECHANISM FOR TYPEwRITERs Filed July 8, 1948 8 Sheets-Sheet 7 HG. EGA

75 Fagwgggg INVENTOR J 69C Ropaf 69D BY 70A 59p ATTQRNEY April 3, 1951 R. D. DODGE 2,547,449

PROPORTIONAL SPACING MECHANISM FOR TYPEWRITERS Filed July 8, 1948 8 Sheets-Sheet 8 FIG. 26

INVENTOR A? l o ATTORN EY Patented Apr. 3, 1951 PROPORTIONAL SPACING MECHANISM FOR TYPEWRITERS Ronald D. Dodge, Poughkeepsie, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York K Application July 8, 1948, Serial No. 37,578 t (c1. isi- 84) 46 Claims.

This invention relates to typewriting machines. The primary object of the present invention is to provide an improved mechanism for spacing` An obj ect is to provide a variable spacing mech- I anism `which takes up relatively little space yet is capable of a relatively largenumber of different degres of spacing to accommodate considerable variation in the Widths of the characters of a font of type used in a typewriting machine.

An object is to provide a variable spacing mechanism suitable for use in a typewriting machine equipped with the power mechanism disclosed in application Serial No. 752,723, filed June 5, 1947, and since issued as Patent No. 2,506,444, dated May 2, 1950, and the shift mechanism disclosed in application Serial No. 756,921, I'lled June 25, 1947, and since issued as Patent No. 2,517,989, dated August 8, 1950.

An object is to provide a variable spacing mechanism which oiiers the least interference with vthe location and operation of other mechanisms associated with the carriage of the typewriting machine, such as the back-spacing mechanism, tabulating mechanism, the margin controlling mechanism, and the carriage return mechanism.

An object is to provide a variable spacing mechanism which is more accurate and more reliable than the variable spacing mechanisms hitherto used in the art.

An object is to provide a variable spacing mechanism which occupies considerably less space in the machine than variable spacing mechanisms hitherto used in the art and avoids the use of 'nating the troubles which'arise when it is attempted to use a ne pitched escapement rack.

An object is to provide a variable spacing mechanism in which certain undesirable conditions arising during the return ofthe carriage and during tabulating operationsare eliminated to enable more accurate margins and columns to be obtained and to insure more accurate and more positive arresting of the carriage in the lefthand marginal position.

An object is to provide means for accurately and positively engaging the escapement pawls with the escapement rack at the end of the carriage return operations to eliminate uneven margins Which commonly result when it is attempted to use ne pitched racks.

An object is to provide a variable spacing mech-- anism which permits returning the carriage and tabulating at a higher speed than was possible hitherto.

y Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, 'which disclose, by way of example, the principle of the invention and the best mode, whichhas been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a vertical section of a typewriting machineincorporating the present invention.

Fig. 2 is a plan view of the variable spacing mechanism and selector mechanism.

Fig. 3 is a rear elevation showing the selector mechanism and spacing mechanism.

Fig. 4 is a plan View of the mechanism shown in Fig. 3.

Fig. 5 is a large scale vertical section on the line 5 5 in Fig. 2.

Fig. 6 is a detail view of one of the selector bars.

Fig. '7 is a large scale plan view of the spacing mechanism and the mechanism for controlling the escapement pawls during carriage return and tabulating operations.

Fig. 8 is a vertical section on the line 8--8 in Fig. '7.

Fig. 9 is a horizontal section on the line 9--9 in Fig. 8.

Fig. 10 is a vertical section on the line lll-l0 in Fig. '7.

Fig. 11 is a large scale rear elevation of the mechanism shown in Fig. 7.

Fig. 12 is a large scale side elevation'of the mechanism shown in Fig. 11 as viewed from the right in that gure.

Fig. 13 is a view somewhat similar to Fig. '7, but showing the escapement pawls held in released position. Y

Fig. 14 is a vertical section on the line |4-I4 in Fig. 13.

Figs. 15A to 19A are a series of large scale detail plan views showing a succession of 'positions Figs. 20A and 21A are views similar to Figs.

15A to 19A illustrating two successive positions of the escapement pawls when two units of spacing take place.

Figs. 20B and 21B are vertical sections corresponding to Figs. 20A and 21A, respectively.

Figs. 22A and 22B are a plan view and a vertical section, respectively, similar to Figs. `21A and 21B, but showing the selective operation of the pawls to determine three units of'spacing.

Figs. 23A and 23B are'similar to Figs. 21A and 21B but illustrate the selection for'four units of spacing'.

' Figs. 24A, 25A, and Y24B, 25B are figures similar to Figs. 21A and v421B, to illustrate operation of the spacing pawls t select lfive units of spacing.

Fig. 26 is a plan view showing the connections for releasing the escapement mechanism from the carriage.

Fig. 27 is a large scale rear view of the means for expanding the spacing.

Fig. 28 is a side elevation of the mechanism shown in Fig. 27 with certain parts broken away.

Fig. 29 vis a detail view of the carriage return release lever.

The numeral ||I designates one of the key levers of which there is one for each character printing type bar and is pivoted on a cross rod II suitably supported in the side vframes l2 of the machine.v Each key lever I0 is provided with a nger button IllAand a restoring spring I3 which urges the key lever |`0 in Va counterclockwise direction (Fig. 1). The forward' or right-hand ends of the key levers are guided in'slots in a' key guide bail I4 which is' suitably mounted in the base I2.

Associated with each key lever I0 is a character printing type b ar I6 which, Vas usual in the art, may be provided with two types I'Ga comprising upper and lower case characters. The type bars I6 are supported in a type basket which includes the usual segment I'l and the type bars I6 are pivoted in the segment .Il by: the usual curved pivot wire I8. -The segment I'l is slotted to accommodate the typeV bars I6 and', since vthe segment is curved, the type bars I6 recline Vat the angle shown in Fig. 1, but at different levels in the machine.

Each type bar I6 is operated by a power unit which includes a sub-lever I9 connected bya link 20 to an extensionv |6B formed Vin the associated type bar I6, whereby the rocking of the sub-lever I9 clockwise, vthrouglrthe link V2|), actuates the type bars I6 in a counterclockwise direction to engage one or`the other of the type'characters Ilia with the work sheet `on the usual platen 2|, the type striking through the usual ribbon. At the printing point the types are guided by a type guide 22 which is secured to the front face or the segment I1. The type' guide 22 also slidably supports a ribbon yvibrator 23 which is mounted o n the upper end of a link 24 pivoted at its lower end to a lever 25 for actuating the ribbon vibrator. Any suitable means may be used for 'actuating the ribbon lever 25.

Thelower end of each sub-lever` I9is formed .to restore the sub-lever 4 with a deep notch |9a which cooperates with a fulcrum strip 26 having a rounded nose 26a and the nose 26a is kept seated in the notch I9a by means of a spring 2`| which is anchored to the lower end of the sub-lever I9 below the notch |9a and to a lug 2Gb in ,the fulcrum strip 26. The spring 21 not only serves to hold the sublever I9 on the pivot or nose 26a but also tends I9 when it has been Aactuated as hereafter described and incidentally assists in restoring the type bar I6 after it has made its impression.

Each power unit includes a somewhat L -shaped cam element 28 pivoted at |9b on the sub-lever I9. This cam 28 -is provided with a restoring spring 29 which is'anchored to an ear 28a formed in ythe cam ,26 and to a lug struck from the lever I9. The cam 28 is provided with a spiral tread 28h designed to cooperate with the power roller 30 which rotates continually in the direction of the .arrow (Fig. 1) lwhile the machine is in use. Normally, however, the upper yend of the tread 28b clears the .power roller 30 with the parts shown in the position of Fig. 1 which is the normal position.

Each cam 28 has an elongated .tail piece v28c which ordinarily is held in engagement with a lug 3|a in the release member 3|, the spring 29 in the position of Fig. l'holding the tail piece 28C against the lug y3|a. .The release member 3| is provided .with a slot through which passes a stud 3 Ib carried by an arm forming part of the sub-lever I9. A spring 32, connected vto an ear formed in the release member 3| just below and to the right of the stud SIb and to a -lug |9`c formed in the arm .of lever I9 carrying stud A3Ib holds the member 3| with the stud 3Ib at the right-hand end of the slot in member 3| and also normally holds member 3| up against the lug |9c. The member 3| has a lug 3| c which just clears a short extension or lug Ib -in the character key I0.

When the character key VI|l is depressed, the member 3| will be rocked slightly counterclockwise by the engagement of the lug Ib with the lug 3| c. This'rocks the cam 28 slightly clockwise sulciently to bring the upper end of the tiead 28h into engagement with the surface of the power roller 30. Thereafter, the power roller 30 drives the cam 28 in a clockwise direction and, due to the eccentric shape of the tread 28h on memberf28, pushes the stud |912 to the right in .a short arcuate path, thereby actuating the sub.- lever I9 in a clockwise direction on pivot 26a and. through the link 20, operating the type bar I6 to effect an imprint from oneof the types IBa.

Before proceeding with the description of the variable spacing mechanism, the space selecting mechanism operated by the power mechanism lfor the type bars will be described rst. This mechf.

anism is shown in Figs. 1 and `2 and Alargely mounted underneath `the keyboard Yjust in front,

that is, to the right in Fig. 1, of the .power rollerA 30. A cross shaft 40 is journalled in the side frames I2 underneath the front ends of the keys IU and adjacent the side frames I2 the shaft 491s circumferentially grooved to vertically guide two support plates 4| in which are loosely pivotally supported the selector balls 42A, 42B, and 42C. Each bail consists of a round rod formed with cranks at its ends with the crank pins pivoted atr 4IA in the plate 4|. The plates 4| are vertically guided at their lower ends by studs 43 carried by the side frames I2 so thatthe plates 4| are com pelled to move vertically and linearly. Secureg Cooperating with. the pawls an campement' rackl having its teeth, located at nter-Vale Qf six unitsof spacing of the carriage and the racl; is wide enough to enable all voi the pawls GBA to 69F to control the feed of the carriage. This rack; is, secured in any suitable manner to the bottom of the channel shaped member 'l5 Figs. 1 and 12) which forms part of the carriage so that the rack 'E5 extends parallel with the rear rail 58 directly below and in front of said rail adjacent the bearing VI for the carriage. Under normal conditions, one of the pawls 69A to Bil-F always engages a tooth of the rack l5 So as to hold the carriage immovable against the tension of the usual carriage feeding spring (not shown).

The four interposers 6l. 55A, 55B, and 55C are arranged in the order named from right to left in Fig. 3, and are spaced apart, center-to-center, a distance equal to one. unit of spacing. In Figs. A to 19A and 15B to 19B, the dot-dash line denotes the position of a theoretical unit interposer for producing one unit of spacing if it were necesary to make provision for such a small de greg of spacing. This theoretical interposer is used as a convenient means of illustrating by a sequence of successive operations shown diagrammatically in Figs. 15A to 19A and 15B to 19B how the escapement mechanism operates in the sim.- plest possible way.

The rst condition to be considered is the condition shown in Figs. 15A and 15B in which the pawl 59By is in engagement with a tooth'in the rack l5 and is holding the carriage immovable. The pawl 69A under these conditions will be just engaging the next adjacent tooth on the ieft of the rack l5, as shown in Fig. 15A, and the remaining pawls 69C to GSF will be held against the tooth engaged by the pawl 69B by their springs 1li. Under this condition, the theoretical one-unit interposer (Fig. 15B) will occupy a position just behind the extreme right-hand end or tail of the pawl 69B but will be clear of the tails of the remaining pawls. If now the theoretical unit interposer is rocked clockwise on the pivot 56 (Fig. l) the pawl SGB will be disengaged from the rack 'l5 and the carriage Ywill be free to move to the right in Fig. 3 under the stimulus of the usual carriage feeding spring (not shown) this causing the rack l5 to move to the right in Fig. 15A.

It will be noted in Fig. 15B that the pawl 69C is capable of moving one unit of spacing to the right before the left-hand end of the mounting slot therein engages the stud 18A. Since this pawl is in engagement with a tooth in the rack l5, it means that the carriage will be permitted to move only one unit of spacing. Of course, all of the remaining pawls 69D, 63E, and GSF will move to the right with the pawl 69C, but the actual amount of carriage movement will be de- -termined solely by the pawl 63C. At the end of this operation, the pawls will assume the position shown in Figs. 16A and 16B.

As soon as the pawl 65B is carried clear of the rack 15, its spring 14 will draw the pawl t0 the left as far as it will be permitted to go by the stud 10A. At the same time, since the pawl 59A is still in engagement Awith the next adjacent tooth on the left to the one formerly engaged by the pawl 69B, the pawl 69A will alsobe moved to the right one unit of spacing and the pawls 69A, 69B will be -aligned as shown in Fig. 16B by the ,tooth in the rack. This movement has pushed the pawl 69C to the right from the po- Seite of. ne., v1.51; to ne mation of Fia ne te plate the .rightehand end r tail 0f the eWIBSQ in the plane of the theoretical one-,unit interi. poser, It now the interposer is operated again, the pawl 69C will be released from rack l5 and pawl 69D Will. Permit the Galrage to mOi/e one additional unit to the right carrying pawl 69D. to the position of Fig, 17B in which the stud 10A acts as a stop to limit the movement of the pawl 65D. The spring for the pawl 65C will draw this pawl to the left until it is stopped in alignment with the pawls 69A, 69B so that, after the sec.: ond unit spacing operation, the parts Will have the position shown in Fig. 17B.

Upon a `fourth and iifth operation of the thee. oretical one-unit interposer,'the pawl 69E (Fig. 17B) and the pawl BBF (Fig. 18B) will permit the Carriage to move two units in succession. With each operation, the selected pawl 697D,l 69E, rofspectively, ,is drawn to the right into alignment. with the previously operated pawls and the next adjacent pawl below the selected pawl permits the carriage to move one unit. At the end yof this series of ve operations all of the pawls save the lowest one, GSF, will have been operated and the pawls 69A to 69E will all have been aligned as showninFiglQB.

If noW the pawl GSF is operated, the pawl 69A will permit the carriag-l to move one more ,unit of spacing and the Ypawls 59A to BSF will take the positions shown in Fig. 20B. Upon still an; other operation of the theoretical one unit inter,-A poser, the pawls 69A, 69B will be operated and the pawl 69B will @110W the carriaeeto more one unit, restoring the assembly of pawls to the 'postion of Figs. 15A and V1511-3.

The `foregoing assumes that it was desired to feed the carriage only one unit of spacing and. under Athe assumed operating conditions, only one of the pawls 69A to 69F is urged into position to be operated by the theoretic one unitinterposer. `Under actual conditions where differ,- ent degrees of spacing are effected by successive operations, several ,of the pawls may be operated at a time but only yone will be effective to limit movement of the carriage. Referring to Fig. 15B, it will be noted that the pawls 69B to BSF are arrayecl in stepped formation with their tails and consequently their mounting slots projecting yto the right, each one an additional unit of spalcfin-g with respect to the others. This means that the tail of the pawl 69C will be in a position to be operated yby the two unit interposer 6I and the pawls 69D, 59E, and BSF will be in a position to be .operated by the interposers 55A, 55B; and 5 5C, respectively.

1t will be noted that in Fig. 20B the paWlGSB has its rightfhand end, as shown by its relation to the dotted line, in position to be operated Aby Ithe two unit Vinter-poser 6I while the pawl is holding the carriage and is in a position to be voperated not only by the two unit interposer but by the theoretical one unit interposer. l:I f now the .operator desires to space the carriage .two units, the pawls 69A and 69B willlboth be operatedand the pawl 69A, which is holding the carriage, and .pawl 69B will be released and will b e drawn `to the'left by their springs 14 into engagement with the next tooth of the rack v'l5 on the leit, as shown in Fig. 21A. The actual movement of the carriage win be limited by the pawl v69C (Fig. 20B) because vthis pawl has not been :disengaged from the tooth in the rack and :it alone is cap/able of moving only two units. Con yseauerltlv. the actual carriage .movement Wilmot H9 determined by'themounting slot in pawl 69C, Vthe left-hand wall (Fig. B) of which is two units away from the stud 'I0 sothat the parts will assume the position shown in Fig. 21B. It VWill be noted by reference to Fig. 21B that although the pawl 69A was released, it did not nally stop at the end length of the slot owing to the fact that the tooth next on the left to the one holding the pawls 69C to 69F in alignment, moves to the right two units, so that the net motion of the pawl 69A is only three units of spacing. With reference to Fig. 21B, it will be noted `that the pawl 69C is now holdingV the carriage and the pawl 69D has been carried into a position to be operated by the two units interposer il. If this interposer is again operated, the pawl 69D will be released and the pawl 69E will permit the carriage to move two units.

' Figs. 22A and 22B illustrate the same condition as prevails in Figs. 18A and 18B in which it will be noted that the tails of the pawls 69A, 69E, and GSF are aligned as shown by the double dot and dash line, so as to be operable by the three-unit interposer 55A. If this interposer is now operated, all three of these pawls will be actuated and the carriage will be released by the pawl 69E with the result that the pawl 69B will permit the carriage vto move three units of spacing. Y

1 Figs. 23A and 23B show the same condition as vfound in Figs. 15A and15B and it will be noted -that the pawls 69B to 69E all are in position to .be operated by the four unit interposer 55B which is` represented by a fine solid line. When this happens, the pawl 69F, which is the only one in ,engagement with the tooth engaged by the pawls V69B to 69E capable of four units of movement,

will limit carriage movement to four units of spacing by moving to the position of Fig. 24B.

i Figs. 24A and 24B illustrate the same condition .as in Figs. 19A and 19B in which all of the pawls except the pawl 69E are in a position to be operated by the ve unit interposer 55C, denoted rby a thick line. When this interposer is operated,

.the pawl 69E is the only one not actuated byV the vfive unit interposer and it remains in contact with a tooth in the rack 'l5 to limit movement lvthereof to `iive units of spacing, the pawls assuming the positions of Figs. 25A and 25B at-the end of this operation.

In Figs. 25A and 25B, the parts have been restored to the positions of Fig. 18B as a consequence of the ve unit spacing from the positions shown in Figs. 24A and 24B. In Fig. 10, the positions of the various interposers, including the ,theoretical one-unit intel-poser, are indicated by 4the small numbers itc 5, designating the same kinds of, lines in Fig. 15B to 24B. f I If it is desired to effect six units oi spacing, it is necessary to release all ofthe pawls from the rack 'l5 and this may be done by shifting the group or interposers 6l and 55A to 55C bodily to the left in Fig. 3, one unit of spacing, so that .the two-unit interposer 6i is placed in the normal position of the three-unit interposer and. the veunit interposer is positioned so as to operate all of the pawls 69A to 69E regardless oftheir positions. j There are six possible combinations or posi- ,tions of the pawls- 69A` to 69E, the rst ve combinations being shown in succession in Figs. 15B to 19B and the sixth in Fig. 20B and any one lof these six positions may precede any one of ive .space selecting operations according to whether two, three,four, iive or six units of spacing are required In each-case there will vbe .as many pawls operated as there `are units of spacing allotted to the letter which is to be printed. It will be noted in examining Figs. 15B to 19B and 20B that, no matter how the pawls are arranged after any given spacing operation, they are always positioned so that two, three,four or ve pawls will be operated for the corresponding number of units of spacing. Y y

This is readily seen in Fig. 25B, for example, il', with this arrangement of the pawls it is desired to space ve units, the pawls 69A, 69B, 69C, 69E, and 69E will be operated and pawl 69D will permit ve units of spacing. If four units of spacing are desired, the pawls 69A, 69B, 69E, 69F will be operated and pawl 99C will determine four units of spacing. If three units of spacing are desired, the pawls 99A, 69E, and 69F' will be operated and pawls 69B will allow three units of spacing. Similarly, two -units Aof spacing will be determined by operating only the pawls 69E, 69F, and the pawl 69A will limit carriage movement to two units. v

The machine may be equipped with the usual tabulating mechanism of the same general type as disclosed in Patent No. 1,935,436. This tabulating mechanism includes a tabular lever v9!) (Figs. 3, 4. and 26) .which is rocked in a horizontal y plane in a well known way about the pivot -91 by power mechanismsimilar to that ordinari-ly used for operating type bars and controlled by the tabular key (not shown). This lever is rocked clockwise in Fig. 4 to place the counter stop lug 99A in the path of a tabular stop (not shown) carried by the/carriage. This movement actuates the usual release lever 92 (Fig. 26) pivotally mounted at 93 on .the top of the rear rail 58 in a well known way. The lever 92 is rocked counterclockwise in Fig. 6 by the tabular lever through the medium of a lug 92A formed therein which extends upwardly in the rear of the Vtabular lever, as most clearly shown in Fig.

V26. This lever 92 also has a lug 92B which pro-r jects upwardly in the path of movement of the usual release bail 94 carried by the carriage and actuated by the usual carriage release levers (not shown) which are pivotally mounted at the ends of the carriage.- These are all details of construction which are well` known in the art and will not be described in detail herein.

The release lever 92 has a lug 92C which, as most clearly shown in Fig. 7, engages the arm 94A of a lever 95 pivoted at 95A on a stud carried by an extension 96A of the plate 96 on which the tabular lever is pivotally mounted at 9i. Pivotally mounted at B is a release lever 91 having an arm 91A which extends to a point under the escapement pawls 59A to69F and is formed with a lug 91B which projects upwardly just to 'the left (Fig. 7) of the extensions'or lugs 12. formed in the escapement pawls. When the tabularlever 90 is actuated in a counterclockwise direction (Fig. 26) or the arm 92.'is actuated in a counterclockwise direction by the release bail 94, the lever 95 will be rocked f counterclockwise (Fig. 7) and the lug 91B,

moving upwardly from the position of Fig. 7 to the position of Fig. 9, will disengage the escape- Vment pawls 69A to 99F from the rack 'I5 and allow the carriage to move freely under the influence of the usual carriage feeding spring.

The lever 91 has an adjustable eccentric stop 98, most clearly shown in Fig. 9, which normally engages an arm 99A of a latch lever 99 pivoted on the stud 95A. This latch lever normally has .the Position. ,Shower-ih Fie; i .Qovperatine with the Vlatch lever 99 is a latch lever |00 pivoted at on a stud carried by the extension 96A of the plate 96. The lever L00 has a bent-over lug 100A projecting into a slot formed ina 'lever |02. As shown in Fig. 8, the lever |02 is vpivoted on a shoulder formed in a nut '|03 threaded on the lower end of a shouldered stud |04 which is received in the bore of a bushing HMA projecting through the block and the extension 96A. The nut |03 clamps together an arm |05 and a lever |06 so that the levers |05, |00 are pivotally mounted on the 'bushing 104A by means of the stud |04 but pivotal movement thereof is not communicated to the lever |02. The latter has an upstanding lug |02A which extends into the rectangular opening |01A (Fig. 9) of a pawl |01 which is pivotally slidably mounted on the pin 10A in the same manner as the escapment pawls 69A to BSF. This pawl |01 is urged to the leit by a spring 14 similar to those which actuate the escapement pawls and is provided with teeth |01B capable of engaging the teeth of the rack 15 but this pawl |01 is not provided with a lug 12 but is actuated by the lug 91B when the carriage is released by hand or during a tabulating operation.

When the latch lever 09 rocks countercloekwise, as described above, it travels from the position of Fig. 7 vto the position of Fig. 9 and at the same time, the escapement pawls and the pawl |01 will be drawn by springs 14 to the left as far as they will go. This permits the lever |00 to be rocked in a clockwise direction by a spring |08. One arm of the lever |00 has a latch lug |00B cooperating with a latching shoulder 99A formed in the lever 99 and the aforesaid movement .of lever |00 moves the lug |00B into a latching relation with the shoulder 99A thus preventing the lever 09 from restoring as in Figs. 9 and 13. Thus, when the bail 04 or the tabular lever 90 is released, a spring |03 restores the lever 95 and the lever 91 to the position of Fig. 7, allowing the escapement pawls and the pawl |01 to reengage the escapement rack but the lever 99 will be held in shifted position temporarily by the lug IB.

The teeth |01B on the pawl |01 are spaced apart three units of spacing and it .should be explained that the teeth on the tabular rack (not shown) carrying the tabular stops are spaced apart three units .of spacing. Owing to this spacing, when the pawl |01 reengages the rack, it will either engage a tooth on said rack between the teeth |01B or one of the teeth in rack 15 will .engage the left-hand face of the left-hand tooth |01B.

The latch lever 99 (Fig, 7) is shaped to form a bail having the cross piece 99B which engages a tooth |05A forming part of the lever 05 which, it will be recalled, is clamped to the side of the lever |06. The levers |05, |06 are adjustabiy connected together by a clamping screw |09 and this assembly is urged in a counterclockwise direction by a spring I09A.

When the escapement pawls 69A to 09F and the pawl |01 are released as described and the latch lever 99 is moved to the position ofy Fig. 9, a lug |00A formed in the lever |05 and extending upwardly through all of the openings 1| in the escapement pawls, moves to the right in Fig. and aligns the pawls4 69A to 09F, as shown in Fig. 14, in which it will be noted that pawls 59A and 69D are three units away from the pin 10A. Thus, when the pawls are allowed to reengage the rack, as at the end of a tabulating operation 12 of the carriage, the carriage 'will 'be allowed to move three additional units vin a letter spacing direction and either pawl 69A will hold the car'- riage as in Fig. 20B or pawl 69D as in Fig. 17B.

The reason for this mode of operation is that the units of spacing are so small that it is not practical to cut teeth on the tabular stop rack at such close intervals as one unit of spacing and the spacing of three units is selected as va ccm'- promise which provides adequate strength to absorb the shock oi tabulating movement and the finest permissible degree of positioning of the column stops. It will be appreciated, of course, that one unit is quite small in relation to the normal spacing of -s of an inch most common in typewriting machines so that three units give a closer spacing of the column stops than would ordinarily be obtained lwith the most common spacing used in typewriting machines.

An advantage of positioning the pawls as in Fig. 14 during tabulating operations, and in car'- riage-return operations, is the more accurate reengaging of the pawls when they are released. There is at least three units of spacing margin for reengagement of the pawls instead of only one unit as would be the case if dependence were placed on any single pawl to drop behind a tooth with a clearance of less than one unit of spacing. In the past fine pitched ratchet wheels of large diameter geared to the rack with relatively high gear ratios have been used to obtain fine degrees of spacing. Due to friction, wear, back-lash of the parts, and springing, it was found to be very difiicult to always catch the right tooth when reengaging the escapement pawl due to the very narrow tooth spacing. The present invention avoids this by in eiect expanding the rack spacing or the spacing of the teeth on the ratchet wheel for the purpose of ensuring accurate co1- umns and margins.

When the carriage moves the additional three units of spacing mentioned above, the pawl |01 is carried to the right (Fig. 9) three units and rocks ythe lever |02 clockwise thereby releasing the latch lug 99A from the latch lever 99 and permits the spring |09A to restore the lever 99 to the posit'on of Fig. 7.

The pawl |01 normally is free to engage the rack 15 and its mounting slot for stud 10A is six units long so that when the pawl is in its extreme left-hand position as in Fig. 9, the left-hand end or tail of the pawl will be clear of the five-unit inerposer when all of the interposers have been bodily shifted to the left in the manner hereinafter described. During the normal spacing movement of the carriage, the pawl H1 travels to the right with the carriage to bring the tail of the pawl into position to be operated by the interposers 6|, 55A, 55B, and 55C so that the pawl |01 can never travel .f ar enough to block carriage movement without being operated by one of the interposers and disengaged from the rack 15. The worst condition which could be encountered would be a series of three two unit spacing operations commencing with the pawl |31 in its extreme lefthand position. This will carry the pawl up to a position in which the tail is oper-able by the interposer 6| so that on the next spacing operation regardless of what the actual spacing is to be, the pawl |01 will be disengaged by at least one of the interposers. It will be recalled that the interposer 6| is operated with every spacing operation al though it may not have any practical effect as one of the interposers may be selectively operated at the same time to effect a higher degree of spac- 13 ing than the interposer 6I effects alone. Thus, the pawl I 0.1 although it is normally engaged with the rack l5, does notinterfere with the normal -spacingmovement of the carriage. The pawl Illl acts asa safety to prevent the carriage from running free to the right-hand marginal stop when it is necessary to operate a type bar by hand during the course of servicing the machine or eiecting repairs. As will be seen hereinafter, there are times when six spaces are desired to be effected under control ofthe expand mechanism and during these operations the pawl I D'I also,

scribed above through the medium of the release ,f

lever 92. This release lover is provided with an upstanding ear 92D (Figs. 4, 12, 26, and 29) which projects into the plane ot the usual carriage-return trip lever I Ill whereby the release lever 92 is rocked counterclockwise (Fig. 26) and thereby releases the escapement pawls ESA to EBF in the manner described above as a preliminary to returning the carriage. The trip lever H projects into the path of the usual left-hand marginal stop I II carried by the marginal stop rack H2 and, during the course of the carriage-return movement, as the marginal stop iII approaches the marginal position, the trip lever H0 is actuated .in the well known way to disengage the carriagereturn clutch and allow the carriage to coast a short distance until it is arrested by the engagement of the marginal stop with the lug 99A formed in the tabular lever 90. The disengagement of the trip lever H9 allows the restoration of the release lever 92 and permits the escapement pawls and the pawl |01 to reengage the rack. The disengagement of the carriage-return clutch allows the carriage to move about three units in a letter spacing direction and the pawl `Illl will be operativeto rook the latch lever 99, as described above, restoring the parts to the position of Fig. 7. The carriage-return mechanism may be of the type shown in Patent No. 1,955,614 which discloses all of the parts except the lug 92D.

It is desirable for certain kinds of typewritten matter to be able to write'the characters, as, for example, the letters of a headng line or matter which is to be specially emphasized, with slightly increased spacing and, accordingly provision is made for bodily shifting the cage 55A and the interposers 6i and 55A to 55C to the left (Fig, 3) for the purpose of changing the selective effect of these interposers on the escapement pawls by one additional unit so that the minimum spacn;r is three units instead'of two and the maximum spacing is six units instead of five. The mechanism for effecting this operation is best shown in Figs. 27 and-28. ,v--Pivoted at H5 on the bracket 5l (Fig. 28) is a Y-shaped lever I I6, the longer arms of which are disposed on opposite sides of a stopstud II I carriedA` by the bracket l. A toggle spring H8l connected to a pin carried bythe right-hand arm' of the lever H5 and to a fixedstud carried by the bracket 5l urges the lever i it in a clockwise direction (Fig. 28) -which is limitedby the Stud II'I. The lever IIS, adjacent its pivot H5, is connected to a vertical link H9 which` as best shown in Fig. 27, is offset to the left and provided with a button I ISA whichbearsagainst .acam surface 10B formed inthe block 'Ill-carrili ing the escapement pawls. g 1 Thelever H6 is connected by a horizontalllink I2() vto a suitable key or operating lever located at the front of the machine which may be actuated .to push the link to the left (Fig. 23) when it is desired to expand the spacing. This rocks the lever I I6 counterclockwise until the right-hand arm of the lever engages the stop stud'I Il thereby drawing down the link II S and causing the button I 59A to travel downwardly over the cam surface 19B. The cage enclosing the interposers 6I and 55A, 55B, and 55C is pressed by a coil spring I2I to the left (Fig. 27) against the right-hand end of the button I IA, thereby compelling the cage andy the interposers to travel to the left one unit of spacing when the button II 9A is drawn downwardly. This causes the. two-unit interposer to assume the position normally held bythe threeunit interposer and theiive-unit interposer assuines a position one unit to the left of that it normally holds. Thus, when the interposers are selectively operated as described above, the twounit interposer causes three units of spacing and the three-unit interposer four units of spacing. Normal operation of the two-unit interposer,` in the absence of selection of the three, four, or iiveunit interposers, causes three units of spacing instead of two units.

If the live-unit interposer is operated withL the cage A shifted as described, all of the escapement pawls will be released and the springs 'I4 Willdraw them tothe left. Taking, ior'example, the positions of Figs. 15A and 15B, this will cause the pawl-'59B to move' iive 'units to the left in a position 'to vengage the tooth in Fig. 15A at the extreme left and the remaining pawls will move to the left in a position to engage the tooth formerly engaged by the pawl SA. 'The carriage'will move six unitsof spacing and the rack 'i5 will travel a similar distance to the right in Fig. 15A and restore the pawls to the positions shown in Figs. 15A and 15B. Although the pawls can only move a maximum distance of five units the carriage actually moves six units because at the instant the carriage starts to move, allowing for the inertia of the carriage, the extreme left-hand tooth in Fig. 15A will be one unit of spacing further to the left than the tooth 'EZA of the pawl 69A. The same general remarks apply to the second, tooth from the left in Fig. 15A with the net result that, at the end of the six unit spacing operation, the pawl 639B still holds the carriage against movementl Regardless of which oi the six basic positions (Figs. 15A to 20A) which the pawls may take the saine action will take place and the parts will always be restored to the condition they formerly had. This is due to that fact that when any tooth is disengagedfrom a tooth, it cannot travel any further than the next tooth onthe leftso that'if the pawls are grouped, some engaging one tooth'and some in a position to engage the next adjacent tooth, when they arereleased, they will always be restored to the original position.`

It is desirable that means he provided to backspace the carriage and in the present case provision is made for back-spacingonly one unit. The back-space mechanism is shownirnostclearly in Fig. 2. Pivoted at 22e on a suitable bracket carried by the rear rail is an arm Iwhioh is connected by Va linkiZl' to a lever i253 pivoted at i' on the rear rail. The lever `28 is provided witha link |39 whichvextends toward the front of .the machine-,eed isf @essere if? a Suite-blason:

unit generally similar in principle to those which operate type bars and controlled by the backspacing key (not shown). The arm |26 is held by a: spring i3! in the position of Fig. 2 against a suitable stop (not shown) and has pi'voted to it at [26A a series of three back-space pawls |32, each formed with two teeth |32A normally clear of the 'teeth inthe escapement rack I5. rIhese pawls are urged in a clockwise direction by springs |33 but, .in the position of Fig. 2, they are held clear of the escapement rack bya stop stud I3@- which limits clockwise rotation of the pawls |32 under the stimulus of the 'spring |33.

' When the link ISS is drawn upwardly in Fig. 2 .by the power unit, the lever |28 is rocked clockwise thereby rocking the arm E25 counterclockwise and carrying the pivoted connection |26A to the leit. This allows the three backspace pawls |32 to swing into engagement with the rack 'l5 and, in the initial movement of the arm |255, the extensions I32B of the pawls are swung close to the rack 'i5 and in a position to engage a bentover lug |35A carried by a suitable plate |35 mounted on the rear rail 53. With further movement of the-arm |26', the extensions |32B move to rthe left and at least one of the pawls |32 will have one or the other of its teeth engaging a tooth in the rack l5 and move the carriage backwardly a little over a unit of spacing which will ybring the extensions |32B into engagement with the lug |35A and arrest further movement of the carriage. The lug |35A and the extensions ESZB are so shaped that the lug |35A acts as a cam to tend to jamthe teeth |32A into the escapeinent rack and prevent overthrow of the carriage, the slight excess movement of the carriage being permitted to insure correct reengagement of the escapement pawls when the carriage is back spaced.

The teeth |32A total six in number and they are disposed diagonally in a vertical plane so that in effect, considering their projections on a horizontal plane, they are spaced one unit of spacing apart with respect to the rack 15. Thus, n'o matter where a tooth in the rack 15 vhappens to be at the start of the back-spacing operation, it will be sure to be picked up by one of the teeth |32A.

The lever |23 also has a link connection |36 with the lever 91 (Fig. 7) which link |36 is drawn to the left thereby rocking the lever 91 clockwise and moving the lug 91B to the right (Fig. 7) into engagement with the lugs l?. on the escapement pawls. This draws the escapement pawls to the right until all of the pawls engage the pin A. This causes the escapement pawls to be arrayed in exactly the opposite sense of Fig. 20B with the teeth 'i2A in a staggered relation. Bearing in mind that the pawls have not been disengaged from the rack by this movement and the fact that the lugs 'EUA are now arrayed in such a fashionas, projected on a horizontal plane, they are one unit of spacing apart, thereis bound to be at least one which will be capable of dropping behind a tooth on the rack and, as soon as the back-space mechanism is restored, the pawl which so acts will be operative to hold the carriage against movement in a letter-Spacing direction. The lever 91 is restored after each operation-by a spring |31 which normally holds the lug 91B Aagainst the block 10 which supports the escapement pawls.

'It is desirableto prevent operation of the backspacing mechanism when the carriage is being tabulated or returned by power. For this purpose the 'lever |05 has an arm provided with a lug B (Fig.- 7') :normally clear of the tails 132C o f the back-space pawls |32. When the lever |05 is rocked clockwise in Fig. 7 to the positionof Fig. 13, the lug IBBB moves to a position immedie ately to the left of the tails |320 and compels the pawls |32 to rock counterciockwise about the lug |05B as a pivot thus preventing the teeth |32A from engaging the escapement rack 15.

While there have been shown and described and pointed out thev fundamental novel features of the invention as applied t0 a preferred embodi'el ment, it will be understood that various omissions and substitutions and changes in the form and details oi the device illustrated and in its operastion may be made by those skilled in the art without departing from the spirit of the invene tion. It is the intention, therefore, to be'limited only as indicated by the scope of thev following claims.

What is claimed is:

'1. In a variable spacing mechanism, an escape-v ment rack movable in a character spacing direc# tion, said rack having teeth spaced apart at uni'- form intervals, each interval being a multiple of a minimum unit of spacing; a series of spacing pawls coacting with said teeth, equal in number to the number of units in said interval, said pawls being of diierent lengths' differing by whole units of spacing, means for mounting said pawls for sliding movement an extent sufficient to enable the rack to move the maximum distance of one interval, and means for disengaging one or more of Said pawls from said rack according to the desired number of units of spacing.

2. In a variable spacing mechanism, a rack having its teeth spaced apart at .uniform intervals, each interval being a iixed multiple of a minimum degree of spacing; and a series of es'capement pawls coacting with said rack, each pawl being independently slidable an extent suii'- cient to permit escapement of said rack one whole interval if all of said pawls are released while one of them is engaging a tooth in said rack, said pawls being slidably mounted different distances from the ends coacting with said rack and said distances differing by whole units of spacing whereby said rack will be permitted to move a number o'f units of spacing determined by the number of pawls released from said rack.

3. In a variable spacing mechanism, a member movable in a character spacing direction and having a series of stop portions disposed at regular intervals, each interval being divided into a xed number of units of spacing; a series of space controlling members equal in number t the number of units in said interval; mounting means for said space controlling members en-y abin'z said rst member to move said space con# trolling'members in a character spacing direction', including means for limiting the strokes of said space controlling membersv by said rst member to progressively increasing distances differing by whole units of said interval, and a selector device for releasing said space controlling members from said iirst member selectively.

4. In a variable spacing mechanism, a member having a series of stop elements spaced at regu# lar intervals, each interval being divided into a xed number ofunits of spacing; a series of space controlling members equal in number to the num; ber of units in said interval and coacting with`v said rst member, any one of said controlling members normally engaging one of vsaid stop elements, said controlling members being mounted for movement by said frst-member-in a charac-y ter spacing direction extents dineringfby-whole units of said interval, said controlling` members`v being releasable from saidstop elements in'one or more combinations to enablethefrst member to move an extent determined* by one off the remaining controlling members; and means for selectivelyv releasing said controlling membersffrom said stop elements.

In a variable spacing mechanism, a member having stop elements located' at equally spaced' intervals, each interval representing @a pluralityV of space increments, andv movable in-a character spacing direction; a series of space controlling stop members movable with said rstmember, each stop member normally engaging one of said' stop elements; means for limitingfthe movement of said stop members to progressively increasing distances which are a multiple of a unit of spacing, one of said stop members normally Aholding said rst membe against movement andfwhen released, allowing the first member to move an extent determined by the stop member having the .next shortest extent of movement which -remains in engagement with a stop element," and means for releasing said-one stop member andone or more of the other stop members tocontrol' the extent of movement or" the first member.

6. In a variable spacing mechanism, amember movable in a character spacing direction and having` a seriesfof stop elements'spaced at regular intervals, each interval being a multiple of a xed increment of spacing; a fixed-stroke limiting element; a series of space controlling stop members engaging said stop elements andy movable by said rst member towardsaidstroke lim'- iti-ng.- member, saidl stop members havingdiierent eiective lengths in relation to -said limitingA element diner-ing by said increment, any one of said stop members normally holding said rst member and, WhenreleasedI-With cneor more of the remaining stop members, allowing said first member to move anextent determined by the unreleased' stop member having the' longest effective length; and means for selectively releasing said stop members, one or more at a time, beginning With those stop members vhaving the longestv effective lengths.

7. In a variable spacing mechanism, afmember movable in a character spacing direction and having'v a series of stop elements disposedon Said member at-regular intervals, each interval being a multiple of a basic space increment, a xed stop, a series of space controlling members equal `to the number of increments in` the interval andshaped to have progressively` increasing'limited movements by said rst member, through engagement with said stop elements, toward saidL fixed stop, and means forreleasing varying numbers of said space controlling members in Vrota'- tion, beginning with the members havingV the shortest movement, according to the number of incrementsof spacing required.

8. In a variable spacing mechanism, an escapement rack movable in a character spacing direction, said rack having teeth spaced apart at uniform intervals, eachI interval being a multiple of a minimum increment of spacing; a series -of spacing pawls coacting with said teeth, equal in number to the number of unitsin said: interval, said paWls being movable by saidrack `different` extents differing by whole units of spacing, aendmeans for disengaging one or -more-o'f said--pawls from said rack inrotation to enable the rack` to` move the desired number of units of spacing.-

.s 9.; I nr .a variable. spacing. mechanism; a -rack having its teeth-spaced apart Vuniform intervals; eachrinterval beingfa fixedf multiple of a minimum degree of spacing and a lseries of escapement pawls coacting with Asaid rack; each pawl being independently slidable anextentsuicient to permit escapement of said rack one Whole interval if--all of said paWls are released while one of them is engaging a vtooth-in saidrac1 ,said pawls being slidablyt mounted dii-ferent distances from the ends coasting-With said rack and said distances differingby whole units of spacing whereby said rackwill be permitted to move a number of units of spacing determined by the pawl unreleased from said-rack which moves the shortest distance.

10. Iii-a variable-spacing mechanism, aV rack movable-ina character spacing direction and having a seriesv orteeth disposed at regular intervals, each interval -being divided into a xedf number of units of spacing; a series of space `controlling paWls-equal in number to the number of 0units in said interval, mounting means for saidpawls enabling saidlrack` to move said paWls in ar character spacing direc-tion, including means for llimiting the strokes of said paWls` by Said rack vto Vprogressively increasing distances differing by one unit of said interval, and a selector device for releasing one or more of said pawls from said rack selectively irl-rotationl l-l-. In a variable spacing mechanism, a rack having its teeth spacedl at regular intervals, each interval being dividedinto a fixed number of units of spacing, a series of space controlling pawls equal in number to the number of' units in said inter-val and engagingthe teeth in said rack, any-one of Asaid pawlsnormally engaging one of said teeth, saidA paWls-being mounted for movement by said rack ina character spacing direction extents diering by whole units of said `interval, said pawls being=selectively releasable from said-rack in oneor lmore' combinations in rotation to enable theraclrto move an extent determinedlby-one of thev remaining pawls, and means for'selectively releasingv said pawls from said rack.

12. In a-variable spacing mechanism, a rack havingfteethv located at equally spaced intervals, each interval representinga plurality of space increments,- -and movable in a character spacing direction; a series of space controlling pawlsY movable with said-rack, each pawl normally engaging one of said' teeth; means for limiting the movement of saidpavvls-'to` progressively kincreasing distances whichare a multiple oi` a unit of spacing, one`V of said pawls normally holding said l rackagainst movement and, when released, al-

, lowing theracltV t'o move an extent determined by thepawliiaving the' next'shortestiextent of movemen-t which remains in engagement with a tooth in said rack; and means for releasing said one' pawl and one or more of the others to control the extent of movement of the rack.

13. Inv a lvariable spacing mechanism, a rack movable in a character spacing direction and having its-teeth spacedat regular intervals, each interval-being a multiple of anxed increment of spacing, a fixed stroke limiting element;` a series of space controlling` pawls engaging the teeth on said'raclcand movable by said 'rack Atowardsaid stroke limitingV element, vsaid ,paWls ,having dif,- ferent effective lengths in relation to said limiting element diering by saidincrement, any one of saidpawls normally holding said rack and, when released'with onev or more ofthe remaining pawls, allowingA said racl; to move an Vextent determined bythe unreleased pawl 'having the longest ,eieci.- tive length: and means for' selectively releasing areas@ said pawls, one or more at a time, beginning with those pawls having the longest effective lengths.

14. In a variable spacing mechanism, a rack movable in a character spacing direction and having teeth disposed at regular intervals, each interval being a multiple of a basic space increment, a fixed stop, a series of space controlling pawls equal to the number of increments in the interval and shaped to have progressively increasing limited movements by said rack toward said fixed stop, and means for releasing varying numbers of said pawls in rotation beginning with the pawls having the shortest movement, according to the number of increments of spacing required.

l5. In a variable spacing mechanism,l van escapement rack having teeth disposed at regular intervals, each interval being divided into a plurality of space increments considerably smaller than the spacing of said teeth; a series of spacing pawls all normally engaging the teeth of said rack and having slots for slidably mounting said pawls for movement in a character spacing direction by said rack, the ends of said slots being disposed different distances from the tooth engaging portions of said pawls, said distances differing by whole increments of spacing; and a pivot extending through said slots and operative to limit sliding movement of the pawls to an extent determined by the lengths of the slots,

any one of said pawls normally holding the rack against motion in a character spacing direction by engagement of the end of its slot with said stop pivot with the ends of the slots in the remaining pawls arrayed different distances from said pivot whereby the release of said one pawl will allow the rack to move in a letter spacing direction an extent determined by the pawl having the end of its slot nearest said pivot, the slots in said pawls being of such length that, when a pawl holding said rack is released, it engages the next succeeding tooth on said rack in a position to allow the maximum movement of said rack when the remaining pawls are released, said slots, when different numbers of pawls are released, permitting the rack to move proportionally different distances according to the number of pawls released, said pawls when released from one too-th engaging the next succeeding tooth whereby the pawls having their slots proportionally nearest the pivot and controlling shorter spacing automatically are aligned by said next succeeding tooth to control longer spacing.

16. In a variable spacing mechanism, an escapement rack movable in a character spacing direction; a series of spacing pawls of graduated lengths representing different fractions of the interval between the teeth on the rack, said pawls normally travelling with said rack in a character spacing direction until disengaged therefrom; and stop means for limiting the stroke of any pawl to less than one tooth interval, said stop means normally engaging any one of said pawls to hold said rack against movement in a character spacing direction, the teeth defining said intervals aligning the remaining pawls so as to permit movement of the rack progressively increasing fractions of a tooth interval according to the number of pawls released, including the one engaging said stop means.

17. In a variable spacing mechanism, a member movable in a character spacing direction and having stop elements spaced at regular intervals equal to the maximum width of a character, a xed stop; a series of space controlling stop members normally engaging said stop elements and movable with said member in a character spacing direction toward said xed stop until arrested thereby, said stop members having different effective lengths with reference to said fixed stop so that only one of said stop members at a time may be arrested by said fixed stop and hold said rst member against movement in a character spacing direction, said one stop member, when released, permitting said movable member to move an extent permitted by that remaining stop member which has the next shortest possible movement permitted by its position in relation to said fixed stop; and means for releasing one or more of said stop members, beginning with the one holding the movable member and ending with the one having the next shortest permissible movement to the one having the desired degree of freedom.

18. In combination with an escapement rack movable in a character spacing direction and having its teeth spaced at uniform intervals equal to the maximum width of a character; a series 0f spacing pawls equal in number to the number of possible widths of characters including said maximum width, and means for mounting said pawls for different degrees of freedom of movement by said rack corresponding to said widths, ranging from Zero to said maximum, all except the pawl of zero degree of freedom normally travelling with said rack to progressively reduce the degree of freedom of allof said pawls, said pawls when released from one tooth being movable into engagement with the next succeeding tooth to restore them to their initial degrees of freedom, such Zero degree of freedom pawl when released automatically resuming its initial maximum degree of freedom.

19. In a variable spacing mechanism, a toothed escapement member having its teeth successively moving in a character spacing direction; a series of space controlling members corresponding in number to a whole number of equal subdivisions of the intervals between teeth of the first member, said space controlling members normally engaging one or more of said teeth, and means for mounting said controlling members so each has a different degree of freedom for movement by the rst member, varying from zero to a maximum corresponding to a plurality of said subdivisions, the member corresponding to the zero degree normally holding said rst member against movement in a character spacing direction and, when released from one tooth in the rst member, being movable to a position to be engaged by the next succeeding tooth so as to have the maximum degree of freedom with respect to the mounting means and permitting the controlling member having the next succeeding degree of freedom to move an extent to limit movement of the first member to such succeeding degree of movement, the remaining pawls progressively decreasing in degree of freedom each time the one having zero degree is released.

20. In a variable spacing mechanism, an escapement rack movable in a character spacing direction; a series of spacing pawls of graduated lengths representing different fractions of the interval between the teeth on the rack, said pawls normally travelling with said rack in a character spacing .direction until disengaged therefrom, a stop for limiting the stroke of any pawl to less than one tooth interval, said stop normally engaging any one of said pawls to hold said rack against movement in a character spacing direction, the teeth dening two intervals aligning the l rack progressively increasing fractions of a tooth interval according to the number of pawls released including .the one engaging said stop; and a series of release .members for said pawls arrayed different .distances from said stop and .representing direrent fractions of said interval, said pawls being moved by said .rack into positionsto be released by said release members whereby the release member1 for any'given, fraction of said interval releases the pawls permitting the next lower fractions of said interval from said rack.

21. In a variable spacing mechanism, a member movable in a character spacing direction and having 'stop elements spaced at regular intervals equal to the maximum Width rof a character, a xed stop; a series of spacecontrolling stop members normally engaging said stop elements and movable with said member in a character spacing direction toward said fixed stop until arrested thereby, said stop members having different effective lengths with reference to said rxed stop so that only one of said stop members at a time may be arrested by vsaid nxed stop and hold said rst member against movement in a character spacing direction, said one stop membei', when released, permitting said movable member to move an extent permitted by that remaining stop member which has the next shortest possible movement permitted by its position in relation to said fixed stop; and means for releasing one or more of said stop members, beginning with the one holding the movable :member and ending with the one having the next shortest permissible movement to the one having the desired degree of freedom; including a series of release members positioned to enable said pawls to beprogressively broughtwithin the control of the release members by movement of the movable member in a character spacing direction, said one stop member being always releasable by all of said release members.

22. In a variable spacing mechanism, .an escapement rack movable in a character spacing direction, said Vrack having teeth spaced apart at uniform intervals, each interval .being a multiple of `a minimum unit of spacing; a series of spacing pawls normally engaging said teeth and equal in number to the number of units in said interval, means for mounting said pawls for sliding movement an extent suincient to enable the rack to move a plurality of different extents up to the maximum distance of one interval; and means for disengaging one or more of said pawls from said rack according to the desired number of units of spacing including a plurality of release members representing `a .plurality of said extents ofspacing and arranged to release said pawls from said rack one or more at a time, each release member releasing as many :pawls as the extent-of spacing it represents, beginning zwith the pawl which represents the shortest spacing.

23. In a `variable spacing mechanism, a rack having its teeth spaced apart at uniform intervals, each .interval being a xed multiple of a minimumdegree of spacing; Aa series of escapement .pawls coacting with said rack, each pawl being` vindependently slidable an .extent vsufficient to permit escapementofsaid rack one Whole interval ifi-al1 of the said pawls are released while one of them is engaging-.a tooth vin said rack, said pawls being slidablymounted .diierent distances from theends. coacting withfsaid rack and said distances diiering by .wholeunitsof spacing- Wherebysaid rack Will-.be permittedito move-.a

v22 numberof units of :spacing udetermined V'by the number fof pawls released from said rack; and releasing lmeans for said pawls including means operable -at differenty points .along the path of sliding movement of saidpawls, and effective "to release different numbers of said pawls.

24. In a variable spacing mechanism, a member movable ina character spacing direction and having a series of stop portions disposed at regular intervals, each interval Abeing .divided into a xed .number of units of spacing; a series of space controlling stop vmembers equal innumber to the number of units in said interval; mounting Vmeans for said stop members enabling said first vmember to move said Ystop members in a characterspacing direction, including means for limiting thestrokes of said stop members by said first member. to .progressively increasing distances .dilering by wholeunits of said interval; and a selector device for .releasing said stop members `from said first member selectively including elements disposednat Ydifferent :points along .the path of travel of said stop members for releasing different numbers/of said stop members .to enable said l'irst member to move different Adistances.

.25. In a variable spacing mechanism, a mem.- ber having a series .of stop elements spaced at regular intervals, each interval .beingdivided into a xed number .of units of spacing; .a series of space controlling members equal in number to the .number of .units insaidinterval and coacting with .said rst member, anyone of said controlling members normally. engaging one of said stop elements, said controlling members beingmounted for movement .bysaid first member ina character spacing direction extents diiering by whole units of saidinterval, said controlling .members being releasable from .saidstopeelementsin one or more combinations to lenable the nrst element to move an extent .determined by one .of the remaining controlling members; and means for selectively releasing Vsaid controlling members from said stop elements, including actuating means effective at different selected points, representing a plurality of the different extents of spacing, along the pathof ymovement ofsaid controlling membersso as to release different co-mbinations of said controlling members.

26. In :a variable spacing mechanism, a member having stop elements located at equally spaced intervals, each interval representing a plurality of spaced increments, andmovable in a character spacing direction; a -series of space controlling stop members movable with said rst member, each stop member normally engaging one of said stop elements; means vfor limiting the movement of said stop members to progressively increasing distances which are a multiple of a unit of spacing, one of said stop members no1'- mally holding said rst member against movement and, when released, allowing the rst member to move an extent determined by the stop member having the next shortest extent of movement which remains inengagement with a stop element; and means for releasing said one stop member and one or more of the others to control the extent of movement of tnerst member, including a series of releasing members arranged to release a progressively increasing number of said controlling-elements beginning with the one which normally holds said rst member.

27. In la variable spacingmechanism, a member movable :in a character spacing direction and having k.af seriesv of stop. elements spaced -at regular intervals, each interval being a multiple of a fixed increment of spacing; a fixed stroke limiting element; a series of'space controlling stop members engaging said stop elements and movable by said iirst member toward said stroke limiting member, said stop -members having different effective lengths in relation to said limiting element differing by said increment, any one of said stop members normally holding said first member and, when released with one or more of the remaining stop members, allowing said rst member to move an extent determined by the unreleased stop member having the longest effective length; yand means for selectively releasing said stop members, one or more at a time, beginning with those stop members having the longest efiective lengths, including a common operating member and a row oi release elements, each representing a different extent of spacing and releasing a different number of said stop members, and means for selectively rendering said release elements operable by the common operating member.

28. In a variable spacing mechanism, a member movable in a character spacing direction and having a series o1" stop elements disposed on said member at regular intervals, each interval being a multiple of a basic space increment, a fixed stop, a series of space controlling members equal to the number of increments in the interval and shaped to have progressively increasing limited movements by said iirst member, through engagement with said stop elements, toward said lixed stop; and means for releasing varying numbers of said space controlling members in rotation, beginning with the members having the shortest movement, according to the number of increments of spacing required, said releasing means including a series of release elements representing a plurality of the increments in said interval and disposed diierent distances from said stop, said controlling members being progressively moved into the inuence of said release elements by progressive space movements of the rst member.

29. In a variable spacing mechanism, an escapement rack movable in a character spacing direction, said rack having teeth spaced apart at uniform intervals, each interval being a multiple of a minimum increment of spacing; a series o1" spacing pawls coacting with said teeth, equal in number to the number of units in said interval, said pawls being movable by said rack different extents diiering by whole units of spacing; and means for disengaging one or more of said pawls at a time from said rack in rotation to enable the rack to move the desired number of units of spacing, said means including a series of operating members representing dilierent extents of spacing into the influence of which said pawls are successively moved by said rack.

30. In a variable spacing mechanism, a rack having its teeth spaced apart at uniform intervals, each interval being a nxed multiple of a minimum degree of spacing; a series of escapement pawls coacting with said rack, each pawl being independently slidable an extent sufficient to permit escapement of said rack one Whole interval if al1 of said pawls are released while one of them is engaging a tooth in said rack, said pawls being slidably mounted different distances from the ends coacting with said rack and said distances differing by whole units of spacing whereby said rack will be permitted to move a number of units of spacing determined by the pawl unreleased from said rack which moves the shortest distance, and means for releasing said' pawls from said rack including a series of release' ling pawls equal in number to the number ofv units in said interval, mounting means for said pawls enabling said rack to move said pawls in a character spacing direction, including means for limiting the strokes of said pawls by said rackv to progressively increasing distances differing by one unit of said interval; and a selector device for releasing one or more of said pawls from said rack selectively in rotation, including a series of release members representing different extents of spacing and disposed transversely of said pawls so as to each be capable of releasing any of said pawls, said pawls being progressively moved into the operating paths of different ones of said release members by progressive spacing movements of said rack.

32. In a variable spacing mechanism, a rack having its teeth spaced at regular intervals, each interval being divided into a xed number of units of spacing, a series of space controlling pawls equal in number to the number of units in said interval and engaging the teeth in said rack,

any one of said pawls normally engaging one of said teeth, said pawls being mounted for movement by said rack in a character spacing direction extents differing by Whole units of said interval, said pawls being selectively releasable from said rack in one or more combinations in rotation to enable the rack to move an extent determined by one of the remaining pawls; and means for selectively releasing said pawls from said rack including means operable at any one of a series of space representing positions and capable of releasing any of said pawls, said pawls being progressively moved past said positions by said rack so as to bring different ones of said pawls into diierent ones of said positions.

33. In a variable spacing mechanism, a rack having teeth located at equally spaced intervals, each interval representing a plurality of space increments, and movable in a character spacing direction; a series of space controlling pawls movable with said rack, each pawl normally engaging one of said teeth; means for limiting the movement of said pawls to progressively increasing distances Which are a multiple of a unit of spacing, one of said pawls normally holding said rack against movement and, when released, allowing the rack to move an extent determined by the pawl having the next shortest extent of movement which remains in engagement with a tooth in said rack; and means for releasing said one pawl and one or more of the others to control the extent of movement of the rack, including a series of space representing release members arranged in a denite sequence whereby the lowest release member in the sequence releases said one pawl and successive members in said sequence release the pawls in a corresponding sequence according to the extents said pawls have been moved by said rack.

34. In a variable spacing mechanism, a rack 

